N-substituted 2-amino-indanes



Patented Feb. 13, 1951 2,541,967 r N-SUBSTITUTED 2-A MINr-INDANES Harold G. Kollo fi, Kalamazoo, Mich., and Nathan Levin, Bloomfield, N. J., 'assignors to Upjohn Company, a corporation of Michigan No Drawing.

Application September 5, 1944, Serial No. 552,822

'6 Claims. (01. zen-570.5)

This'invention relates to a new class of amines having the formula:

I CH2 X wherein X represents hydrogen or a methyl radical and Y represents hydrogen, a hydrocarbon radical, or a substituted hydrocarbon radical, and to salts thereof.

Members of the new class of compounds herein disclosed have been prepared and certain of their physical properties have .been determined whereby they may be identified readily. These new compounds are particularly useful as bronchodilators having little or no effect on the blood pressure.

. Compounds having the above formula wherein X represents hydrogen and Y represents a hydrocarbon or substituted hydrocarbon radical may be prepared by condensing Z-aminOindane with an aldehyde andreducing catalytically the resulting azomethine or Schiffs base, to form thesecondary amine. By methylating the secondary amine with formaldehyde according to the method of Eschweicher (Ben, 38, 880 (1905) a methyl group may be introducedinto the X position and by methylating the azomethine intermediate, using a modification of the method of Decker and Becker .(Ann., 395, 328 (1913)) a quaternary ammonium salt is formed which may be hydrolyzed to form 2-methyl-amino-indan e.

'Z-fAmino-indane, the starting material for the preparation of these new compounds according t'o'the hereindescribed methods, has been prepared and described by Kenner and Mathews (J.- ChemQSoc. 105, 745 (1914)), by Huckel, Yanschulewitsch, Sacks and Nerdel (Ann. 518, 155 (1935)), by Borsch and Pommer (Ber., 54, 102 (1921)), and ,by Benedickt (Ann. 275, 351

( 1 893)). Forthe present purpose Z-amino-inlane was prepared from 2-bromo-1-indanol obtained in turn from indene by the method of Suter and'Milne J.Amer. Chem. Soc.,-62, .3473

(1940)), by reacting 2-bromo-1-indanol with 80- dium methylate according to the method of Heusler and Schieifer (Ben, 32, 28 (1899)), to form 2-methoxy-1-indanol which wasthen hydrolyzed to'2 -indanone. 2-'Indanone was converted to the oxime; and the oxime reduced cat-.

alytically using an active palladium catalyst. iThefree-Lamines of the invention are oily liquids or..lo.wemelti.ng.. solids. which darken when exposed to, theair. They dissolve. indilute aque-J.

ous mineral acids, such as hydrochloric, hydrobromic and sulfuric acids, and form salts which may be recovered in well-defined crystalline form. The amines are only slightly soluble in water but soluble in most organic solvents. The hydrochloric acid salts may be recrystallized from dilute ethanol or from a mixture of ethanol and ether. The amines are conveniently. recov-. ered, stored, and used in the form of their salts, e. g. their hydrochlorides.

In preparing the new compounds, azomethines were first prepared by reacting 2-amino-indane with an appropriate aldehyde according to known methods of preparing this class of compounds. Since Z-amino-indane'was ordinarially isolated and stored in the form of its hydrochloride, the preparation of the'azomethines was usually car-v ri-d out by heating approximately equi-molecue lar proportions of the hydrochloride, the'alde-' hyde, and of sodium bicarbonatetogether in alcoholic solution. The azomethine crystallized from the solution upon cooling and diluting with water. Recrystallization was efiected, when de-, sired, from dilute alcohol. .i

Catalytic reduction of the azomethines was accomplished readily by treating the compound in glacial acetic acid or in alcoholic solution'with hydrogen e. g. in aParr catalytic hydrogenatolt (Organic Syntheses, Coll. vol. 1, (1941), p. .61). using Adams platinum oxide catalyst. Reduc tion was usually complete in from 1 to 4 hours under a hydrogen pressure of from about 1 to '5i atmospheres, or higher, and a temperature of? from about 10 to about 10 centigrade. Other. temperatures and pressures may, of course, be employed. After the absorption of hydrogen had ceased, the solution was filtered to remove the catalyst, the filtrate acidified and concentrated. under slightly reduced pressureand finally dried under vacuum. Recrystallization of the residuewas usually efiected from a mixture of ether and anhydrous alcohol, the secondary amine being recovered in the form of its hydrochloric acid salt.

Methylation of secondary amines, prepared as indicated above, was accomplished by prolongedv heating of the hydrochloride of the amine with; sodium bicarbonate and formaldehyde in'aque ous solution, usually with the addition of formic;

acid. The use of a moderate excess of formal formaldehyde.

colorless crystals of the tertiary amine were precipitated from the filtrate by adding sodium hydroxide. Recrystallization of the tertiary amines was effected from hot dilute alcohol when desired.

The azomethines formed by condensing 2- amino-indane with an aldehyde, such as piperonal, were methylated using a modification of the Decker and Becker method employing dimethyl sulfate instead of an alkyl halide and the quaternary ammonium salt thus formed then hydrolyzed. The methylation of the azomethines was carried out by dissolving the azomethine and freshly distilled methyl sulfate in an anhydrous organic solvent inert under the conditions or the reaction, for example, ethylbenzene or xylene, and heating the solution for several hours at about 100 centigrade. The solution was then cooled and diluted with aqueous methanol for other low-boiling alcohol and the mixture refluxed to destroy the last traces-of methylsulfa te. Therefiuxed'mixture was acidified and'the methanoland inert solvent were vaporized and the aqueous solution remaining was cooled, extracted with ether, and made strongly alkaline with concentrated aqueous ammonia. 2-Methyl-aminoindane was isolated in the form of its hydrochloride by extracting the ethereal solution with dilute hydrochloric acid. The acid extract was evaporated to dryness and the residue recrystallized from a mixture of ether and anhydrous ethanol.

'Other methods for preparing the compounds of the invention may be employed, if desired, and the invention is not limited as to such method. "The following examples are given by way of illustration but are not to be construed as limiting:

Preparation 1.-2-Bro'm'o-1 -indcmol 2-Bromo-1-indanol was prepared in 85 per cent yield from indene. by the method ofSuter and Milne.

Preparation 2.2 -Methoa1y-1 -indanol Thi intermediate compound was prepared by adding 127.8 grams (0.6 mole) of '2-bromo-1- indanol to a solution of grams (1.3 moles) of sodium in 300 milliliters of anhydrous methanol and refluxing the mixture for 1 hour. Approximately one half of the methanol was then evap- Qrated and the remaining mixture diluted with about 1 liter of water. Upon'cooling, the dark oil which separated was extracted with ether.

The extract was dried overanhydrous potassium carbonate, the solvent evaporated and the product distilled. A yield of 79.4 grams, or 82.4 per centof the theoretical amount,-of Z-methoxy-lindanol was obtained by distilling at 149-152" centigrade at a pressure 11-12 millimeters of mercury.

Preparation 3.2-Indanone merizes to a resin upon standing, even at low temperatures. Its immediate conversion to the oxime is, therefore, desirable.

Preparation 4. -Indanone-oazime A solution of 29.7 grams (0.225 mole) of 2- indanone in milliliters of pyridine was mixed with cooling and agitation, with a solution of 18.8 grams (0.270 mole) of hydroxylamine hydrochloride in 60 milliliters of dilute ethanol. After standing at room temperature for 48 hours the mixture was added, with stirring, to 500 milliliters of ice water and the precipitated oxime filtered with suction and washed well with cold water. After recrystallizing from 50 per cent ethanol there was obtained 31.5 grams, or 95.2

.-'per cent of the theoretical amount, of 2-indanone oxime in the form of colorless crystals decomposingat 152-153" centigrade.

Preparation 5.-2-Amirio-indane hydrochloride An active palladium catalyst was prepared by shaking one part of palladium chloride with 9 parts of activated carbon (Norit) "in a 1.0 normalv aqueous sodium acetate solution. The mixture was filtered, the catalyst washed with alcohol on the filter, and kept moist with alcohol during storage and handling to'prevent-"its catching fire.

To a suspension for 424 grams (0:03 mole) of Z-indanone oxime in '100-"milli-liters of "anhydrous ethanol containing 3.3 grams (0.09 mole) 'of hydrogen chloride there was added 3 grams of active i palladium. catalyst and 0.3 gram of *crystalline palladium chloride. The mixture was shaken in an atmosphere of'hydrogen at-atmospheric pressure and ordinary room temperature for about 8 hou'rs, at the end of'which 'time the absorption of hydrogen had ceased. The reaction mixture was warmedpn the steam-bath to dissolve the amine hydr'o'chlorideand the'cataIyst separated by filtering. The filtr'ate' was concentrated in a current'of dry air andnnany dried under vacuum. The crystals-of 2-'amino-indane hydrochloride, a fter recrystallizationfrom a niixture of anhydrous thanol -ancl- 'ethr,-* darkened at 220 cen-tigr'a'de. nyiem o'f'429 'grams, 'or 96-13 per cent of thethebreticaramoent, of the hydrochloridewas thus'obtai-ned.

Preparation 6.- 2'-BenzaZamino-indane I EI OF UH N&GH 1CSHE A mixture of 8f5igrarns (0.05 mole) of 2 aniinoindane hydrochloride, 5 milliliters (0.05 mole) :of benzaldehyde, 4.6i grams (0.055.:mole) of sodium bicarbonate, and 75 milliliters of alcohol was=- refiuxed f0r-2 hours. The-mixture was then-cooled to room temperature,diluted-with 200 milliliters of water, and the crystals of 2-ben'zalaminoindane which separatedwere recovered by filtering and dried withsuction. Recrystalliza tion-of the product from dilute alcohol with the addition of a. small amount or decoloriaing T charcoal gave 10.3 grams, or"95.5 percent of thetheoreti'cal amount, of Z-benZaIamino-indane in the-form ofcolorless crystals meltngat'58-"67'9 centigrade. The prodnot appeared tobe a dimorphic mixture. IA sample of the product was iec'rystamzed repeatedly from "petroleum etlfer without significant mange in the 'meltingpoiiit. Analysiscf the-recrystallize d product gave'the'fo'llowing values:

Preparation 7.-+2 Piperonylidineaminoindane This compound was prepared by :the method :'of'

the preceding .example'ffroni a-pmixture of 5.1 grams ;(0 -.j03 .mole) .of .2-.amino-indane hydroi'chloride, 4:8..grams: (0.032 mole) of:piperona1, and 2.6 grams (0.031 mole) of sodiumibicarbonaterin 150 milliliters :ofethanol. The product upon-re!- crystallization frornafifljpericent methanol was .obtained in the formrofcsmall colorless needlesmelt, ing at 93;5.-:95:5 -.centigrade. grams, or 79.2 per cent of the theoretical amount. Analysis of the recrystallized product gave "the following .values:

g Calc. for C17H15NO2 5.28 Found 5.07

le. .lfor .QMHHH 1., Found 5.70

Example 7 1.-.+g-Bengylamino-ind ne hydrosa o nt on or .51. grams 0.0. mole) o 2- benzalamino-indane (Preparation 6) in rnillii ers-of. anhydrous ethanol co tainin about .0 ra v of 'n a in mzoxide cat lyst. was .shals n ina atmosphere of hydrogen at a temperature of about 28 centigrade and a pressure of slightly more than one atmosphere for about 3 hours. The hydrogenated mixture was filtered to remove the catalyst, acidified with dilute hydrochloric acid, and evaporated to dryness. The residue was recrystallized from dilute ethanol. The product ob-- tained weighed 4.6 grams, which was a yield of 90 per cent of the theoretical amount. The product began to darken at about 205 centigrade. Analysis of the product gave the following values:

. Example 2.-2-Piperonylamino-indane hydro- 2-Piperonylidineamino-indane (Preparation 7) was reduced with hydrogen in an anhydrous ethanol solution as in the preceding example.

From 5.3 grams (0.02 mole) of piperonylidinev.amino-indane there was obtained 5.9 grams of 96.7 per cent of the theoretical amount, of 2- The yield was 26.3

r 6 piperonylamino indane hydrochloride- Lin the form of rles flak szdecom osine a centigrade. Analysis of the prod ct gave the followin; values.

V or oalrqroflnmorNoz 4.61" 11.7 Foundu' 7 4:74 ll.8-'

Example" 3-2 peMethory-b nzylomi orimne hydrochl ride o.nl-cnz-.on-.Nn-ong olnl- 0 0113501 on, Sgrams (0.02 mole) of Z-anisalamino-indane (Preparation .8) was dissolved in .50 milliliters of glacial acetic aci and reduced with hydrogenas. in-the preceding example. The hydrochloride of 2 p. methoxybenzylamino) 1- indane was .ob--

tained, after recrystallization from :a mixture. of methanol and acetone. in the form of colorless flakes which decomposed at 233 centigrade. The yield was 5.4 grams, or-93.1 per centof the .theoretical amount. Analysis of the product gave the following values:

Eramplc e4-..-.2-Methzllamino-indane. hydrochloride CQH4GHZ--QHNHCH;EHOI

' CH2 I A. mixture of 5.6 grams (0.02 mole). .of 2-piperonylidine-amino-indane (Preparation 7), 2.9. milliliters (0.03 mole) of freshly .distilled methyl sulfate, and milliliters of anhydrous ethyl benzene was placed in a BOO-milliliter around-bottomed flask I and the air washed horousi iv-fi om the flask withnitro en; Th

topper dfiask was heated-onthezsteam ba h-for Q hours-at theiend oiwhiohtime adark oil had:

removed by distillation, and the ethyl benzene" removed in a current of steam. The aqueous solution remaining in the flask was extracted with ether and then made strongly alkaline with concentrated aqueous ammonia. The alkaline solution was again extracted with ether and the extract shaken with dilute aqueous hydrochloric acid. The acid aqueous layer was evaporated to dryness and the residue recrystallized from a mixture of anhydrous alcohol and ether with the addition of a little decolorizing charcoal. The

product thus obtained consisted of 0.8 gram, or

21.6 per cent of the theoretical amount, of 2 -methylamino-indane hydrochloride in the form of colorless crystals decomposing at 210 centigrade. The product'had the following analysis:

N Cl

I ExamplejF z-Renew-methylamino-indane mm-oHi-CH-N-om-olm CH CH! A mixture of 2.6 grams (0.01 mole) of 2-benzylamino-indane hydrochloride (Example 1), 1.3 grams (0.015 mole) of sodium bicarbonate, 6 milliliters of comercial formalin, and 10 milliliters of water was shaken and warmed until the initial reaction was completed. Ten milliliters of formic acid was then added and the mixture refluxed on the steam bath for 48 hours. The resulting tancolored, clear solution was acidified with 5 milliliters of concentrated aqueous hydrochloride acid and evaporated on the steam bath to dryness. The crystalline product obtained was dissolved in water and decolorized with charcoal. The cooled and filtered solution was alkalized with aqueous sodium hydroxide and the colorless crystals which separated were filtered from the solution and then recrystallized from hot, dilute ethanol. The recrystallized product melted at 56-5'7 centigrade. The yield was 2.0 grams or 90 per cent of the theoretical amount. The crystals had the following composition:

. N Calc. for C17H19N 5.91 Found 5.90

Example 6.-2-BenzyZ-methyZamino-indane hydrochloride Calc.forC1 HzuC1N 5.12 12.98 Found 5. 49 12. 57

, Qther salts of 2-benzyl-methylamiii'o indane,

such the sulfate and. hydrobromid'daswell as sa s of other Nesubstituted 2-amino-indanes,

8 may be prepared readily. by reacting the amine with the appropriate acid. Salts with organic acids may also be prepared if desired.

Numerous aldehydes, other than those mentioned, may be condensed with 'zeamino-indane and theiresultingt azom'ethines utilized in ways analogousito those described in the preceding examples to form'N s'ubstituted 2-amino-indanes. Among the aldehydswhich may be so employed may he mentioned acetaldehyde, butyraldehyde, propionaldehy'de, "alpha'i-phenyl acetaldehyde, phenyl-aceta'ldehyde; i cycloh'exyl acetaldehyde.

chlorobenzaldehyde, tol'ylald'ehyde, xylylaldehyde,

and many others.

-Weclaim: m' I '1. A compound of the group consisting of (a) N-substituted 2-amino-indanes having the for- HAROLD G. KOLLOFF. NATHAN LEVIN.

' REFERENCES CITED The following references are of record in the file of this patent:

Chem. Abstracts, vol. 11, p. 2676 (1917).

Chem. Abstracts, vol. 20, pp. 755, 756, and 2156 (1926).

Chem. Abstracts, vol. 25, pp. 2138-2139 (1931).

Suter et al, J. Am. Chem. Soc. 62 (1940). p. 3473. 

1. A COMPOUND OF THE GROUP CONSISTING OF (A) N-SUBSTITUTED 2-AMINO-INDANES HAVING THE FORMULA 